Hi, thank you for asking healthcare Magic. Asbestos exposure can lead to a condition called asbestosis. During this disease, there is scarring of lung tissues. This might reduces the exchange of gases in the lungs and less oxygen would be absorbed into the system. The heart reacts by increasing the rate at which it beats to meet up oxygen demands in other tissues. I think this might have been the cause of his high pulse rate. He still needs to be assessed clinically by asking if he has been experiencing chest pains or coughing. Also a chest X-ray or chest CT scan is necessary to rule out this condition. I would suggest he sees a chest medicine specialist for proper assessment. I hope that helps. I wish him well